Optimum Size for Clay Core of Alavian Earth Dam by Numerical Simulation

Seepage in embankment dams is one of the important factors in stability and dam’s maintenance. Core in earth dam is essential for waterproofing and controlling of seepage. Therefore, selection of proper materials and sizes for core of earth dam are very important. Thick clay core is proper for waterproofing but because of low shear strength of the clay, it would be dangerous for dam’s stability. The optimal core would be the core which has proper waterproofing, stability safety factor and also with economic condition. In this study, the aim is to determine the optimum size for clay core of Alavian dam near Maragheh city in steady state seepage condition. For this purposes, Geo-Studio pack is used for numerical simulation. In addition, simulation of seepage and slope stability for the built maps of the dam, 11 more models of the dam with different size of cores were tested to find the optimum core thickness. From these models, data required for objective function and constraints using regression techniques for seepage, hydraulic gradient and stability safety factor were provided. Results showed that optimized volume of the core is 35% smaller than the present core.